Infrared (IR) light refers to light with wavelength longer than that of visible light, and as such is not visible to the human eye. IR light is often used in devices such as television and audio visual equipment which have remote controls to pass signals from the remote control unit to a receiver in order to control the device, for example turning on a television from standby power or changing channels, adjusting volume and so forth.
These remote control units emit a modulated IR signal. This enables a range of codes to be generated by the remote control unit, typically a different code for each button or control on the remote control unit. Further, different manufacturers of infrared remote controls use different codes and different protocols to transmit the commands to remotely controlled devices.
Audio-visual equipment is typically not put into a completely off state where no power is drawn by use of a remote control. This is in order to maintain a state of readiness so that operating power is provided when the appropriate button is selected on the appropriate remote control. This means that the equipment continues to use power at all times, even when apparently not operational. This continual consumption of power can be both costly and a waste of resources.
In order to reduce the consumption of standby power it has been suggested that the device be switched off at the main electrical inlet. However, this is inconvenient as it requires ready access to the wall mounted plug of the audio-visual device in order to switch on and switch off. In many installations users do not have ready access to the wall mounted plug. Even where access is reasonably convenient, users may not be motivated to make the effort to switch the wall socket off after each use. Overall there is a low level of compliance by users.